1. Field of the Invention
The present invention relates to an image projecting apparatus, projecting an image by projecting light onto a recording medium in which the image is recorded, and a luminous apparatus used for the image projecting apparatus, and an image projection converting apparatus, converting the image, projected by projecting light onto the recording medium in which the image is recorded, into an electronic image.
2. Description of the Related Art
An image projection converting apparatus called telecinematography apparatus which converts a movie film in which an image is recorded into a video image is known. Generally the telecinematography apparatus transports a movie film intermittently and projects an image by projecting light onto each of frame images, while performing electronization of the projected image with an image pickup device to convert it into video signals.
According to such image projection converting apparatus, as a wide bandwidth including three colors R(red), G(green), B(blue) and a sufficient light-emission quantity are required for a luminous source, emitting light to be projected onto the movie film, a luminous source such as a xenon lamp, for example, is widely used.
However, in such luminous source, inert gases sealed in a housing produce convection by heat-producing, causing light-quantity variation called flicker. Therefore, the level of light projected onto the movie film varies, resulting in frame-by-frame variation of the intensity level of the projected and picked-up electronic image, i.e. a problem of deterioration of the quality of the obtained image.
The problem does not only relate to an image converting apparatus such as the telecinematography apparatus, but also to a typical projector used in a cinema theater, for example, or to a liquid crystal image projecting apparatus, configured to project an image formed by a liquid-crystal display device onto a screen.
It is an object of the invention to provide a luminous source apparatus, an image projecting apparatus, and an image projection converting apparatus for suppressing harmful intensity variation of a projected image.
A luminous source apparatus of the invention, being used in an image projecting apparatus, which performs image projection by projecting light onto a recording medium in which an image is recorded, comprises: a luminous body emitting light to be projected onto the recording medium; means for detecting the light-quantity emitted from the luminous body; and means for regulating the light-quantity emitted from the luminous body based on the result of the detection by the means for detecting the light-quantity, so as to make the light-quantity projected onto the recording medium constant. A recording medium may be implemented with a movie film, or a group of liquid-crystal display device, for example.
An image projecting apparatus of the invention, performing image projection by projecting light onto a recording medium in which an image is recorded, comprises: a luminous body emitting light to be projected onto the recording medium; means for detecting the light-quantity emitted from the luminous body; and means for regulating the light-quantity emitted from the luminous body based on the result of the detection by the means for detecting the light-quantity, so as to make the light-quantity projected onto the recording medium constant.
Another image projecting apparatus of the invention, performing image projection by projecting light onto a recording medium in which an image is recorded, comprises: a luminous body emitting light to be projected onto the recording medium; means for detecting the light-quantity emitted from the luminous body; means for closing and opening the light-path from the luminous body to the recording medium; and means for controlling the opening/closing operation of the means for opening/closing light-path based on the result of the detection by the means for detecting the light-quantity, in order to make the accumulated light-quantity projected onto the recording medium constant. The means for controlling opening/closing light-path may be configured to begin the accumulation of the light-quantity detected by the means for detecting the light-quantity at the point of making the means for opening/closing light-path in opened state, and to make the means for opening/closing light-path in closed state at the point of the accumulated light-quantity reaching to prescribed value. Or the means for controlling opening/closing light-path may also be configured to accumulate the light-quantity detected by the means for detecting the light-quantity for a given period before making the means for opening/closing light-path be in opened state, while obtaining the opening period of the light-path of the means for opening/closing light-path based on the accumulated value, and to make the means for opening/closing light-path be in opened state for the obtained opening period of the light-path. The means for opening/closing light-path may be implemented with a liquid-crystal shutter.
An image projection converting apparatus of the invention, performing image projection by projecting light onto a recording medium in which an image is recorded and converting the projected image into an electronic image, comprises: a luminous body emitting light to be projected onto the recording medium; means for detecting the light-quantity emitted from the luminous body; means for picking-up image projected by projectinglight from the luminous body; and means for regulating intensity level of the image signal obtained through the means for picking-up image, based on the result of the detection of the means for detecting the light-quantity.
According to the luminous source apparatus or the image projecting apparatus of the invention, the light-emission quantity of a luminous body is detected by the means for detecting the light-quantity, and the light-emission quantity of the luminous body is regulated based on the result of the detection. Hereby, the light-quantity projected onto a recording medium is regulated to be constant, resulting in reducing the harmful intensity variation of an image projected by light.
According to another image projecting apparatus of the invention, the light-emission quantity of a luminous body is detected by the means for detecting the light-quantity, and the light-path from the luminous body to the recording medium is closed and opened, based on the result of the detection. Hereby, the accumulated projected light-quantity is regulated to be constant, resulting in avoiding the intensity variation of the projected image caused by the light-quantity variation of the luminous body.
According to the image projection converting apparatus of the invention, the light-emission quantity of a luminous body is detected by the means for detecting the light-quantity, and the intensity level of the image signal obtained by the means for picking-up image, which picks up the image projected by projecting-light of the luminous body, is regulated, based on the result of the detection. Hereby, the intensity variation of the picked-up image signal caused by the light-quantity variation of the luminous body will be avoided.
Other and further objects, features and advantages of the invention will appear more fully from the following description.